Hydrochloric Acid → Methyl 3-cyclohexyl-1H-indole-6-carboxylate

Participants

Reaction Steps

A 2 L flask equipped with a dropping funnel and mechanical stirrer was charged with crude 3-cyclohexyl-6-indole carboxylic acid (99.4 g, 0.409 mole) and anhydrous DMF (665 mL) was added followed by anhydrous potassium carbonate (78.13 g, 0.565 mole). Iodomethane (63.72 g, 0.449 mole) was added dropwise over 35 min with stirring to the slurry which was then stirred overnight at room temperature until complete disappearance of starting material (TLC). The resulting suspension was then poured into water (1350 mL) and acidified to pH 4 with 4N HCl (200 mL). The product was extracted into ether (3×1700 mL), washed with water and brine and dried (Na2SO4). Volatiles were removed under reduced pressure and the residue was triturated with hexane (700 mL). The beige solid was filtered and dried under vacuum (94.3 g, 90% yield).

Provenance & Evidence